Previous studies have taken various global pooling approaches:
VGGish[1]}, OpenL3[2]}, and COALA[3]} flatten frequency bins, time frames, and channels into a single embedding vector. COLA[4]}, TRILL[5]}, ESResNe(X)t-fbsp[6]}, and Fonseca et al.[7]} use the global average or max pooling commonly used in image CNNs.
